Why do Greys pluck?

[GreenWing]

I visited some Congo African Grey parrots last evening that were older birds in need of a rehome. One in particular "chose" me right away, and I will admit that I wanted to take the little guy in, too. He had plucked all chest feathers and was just so sweet, talking to me quite a bit. Gah, this bird, I want to adopt him but don't have the money. <3
Anyway, I noticed ALL of the Greys were pluckers. They were on solar schedules, so I was wondering why these sweet birds were plucking? Is it stress? Loneliness? Chance does not pluck fortunately, but she also receives a lot of attention and is in good health...

So, I'm wondering, what is the main reason African Greys pluck? Is it almost always psychological?

[Pajarita]

In my personal opinion, all plucking in parrots is almost always psychological -and when I say 'almost always', I am actually being EXTREMELY conservative because, in my personal experience, there hasn't been a single plucker that did it out of a medical reason [except for budgies and amazons which, in my personal experience, only pluck when they are sick]. I think that some species are more prone to others because they need more attention... species like Grays, toos and quakers and, of course, the occasional poor little aviary ones that people insist on treating like a companion species, like plets or lovies which always seem to end up plucking when kept by themselves.

In the case of these birds that are out for adoption, I am sure it was negligence that did it. Everybody wants a super smart, talking African Gray but 99.99% of the people who want them don't have a lifestyle compatible with keeping a bird - any bird, but much less a gray.